"It is the sauce that distinguishes a good chef. The Saucier is a soloist in the orchestra of a great kitchen." - Fernand Point
So true! You can saute a chicken breast to perfection and make a great meal, but if you know how to make simple pan sauces, you can prepare a hundred different meals. Furthermore, you are going to find every cuisine has it's own style of sauces, some similar, some completely different.
For example, Italian sauces for pasta like a Genovese sauce are much different from classic French sauces like a demi glace sauce. A simple soy ginger sauce for Chinese dumplings looks and tastes different from an Indian curry sauce. Even barbecue sauces can be different depending on where you live.
So here are some of my favorite sauces from various cuisines that you can enjoy with your favorite meals.